Bearings, courses, tracks, headings, radials, miles

This regulation establishes the default units of measurement used throughout instrument approach procedures and related charts.

Magnetic reference: All directional information—bearings, courses, tracks, headings, and radials—is magnetic unless specifically marked otherwise (such as "true"). This matters because your heading indicator and VOR displays use magnetic references, so you can fly the procedures directly without conversion.

Distance measurements: The regulation distinguishes between two types of visibility and distance:

• RVR (Runway Visual Range) values are always in feet
• General visibility requirements are in statute miles
• All other distances (like DME fixes, holding pattern leg lengths, or missed approach distances) are in nautical miles

Understanding these defaults prevents confusion when reading approach plates. For example, if you see "3 miles" on a chart without qualification, you know it means 3 nautical miles. If visibility is listed as "1," that's 1 statute mile, but RVR will always show a number like "2400" meaning 2,400 feet.

*This is a plain-English summary for study only. The official 14 CFR text on this page is controlling — always read the current regulation and consult a CFI.*